Hypertension in older adults in Africa: A systematic review and meta-analysis
April
Hypertension in older adults in Africa: A systematic review and meta-analysis
William Kofi BosuID 0 1
Siobhan Theresa Reilly 1
Justice Moses Kwaku AhetoID 1
Eugenio Zucchelli 1
0 Department of Public Health and Research, West African Health Organisation , Bobo-Dioulasso , Burkina Faso , 2 Division of Health Research, Faculty of Health & Medicine, Lancaster University , Lancaster , United Kingdom , 3 Department of Biostatistics, School of Public Health, University of Ghana , Legon, Accra , Ghana
1 Editor: Geofrey Musinguzi, Makerere University School of Public Health , UGANDA
-
OPEN ACCESS
Funding: The authors received no specific funding
for this work.
Competing interests: The authors have declared
that no competing interests exist.
Background
Findings
Conclusion
The persistent high prevalence of hypertension among older adults in Africa, even in rural
populations warrants more attention to the cardiovascular health of this group by public
health authorities.
Introduction
High systolic blood pressure is the leading risk for deaths in Africa. It resulted in nearly
900,000 deaths (10% of the total deaths on the continent) in 2016 and has increased by 82%
since 1990 [
1
]. It is also responsible for more than half of first time acute stroke in Africa [
2
]. It
is also a potentially modifiable risk factor for dementia, a disease of concern in Africa where
ageing, stroke and other cardiovascular diseases are rising [
3, 4
]. A number of systematic
analyses of hypertension in adults and in adolescents in Africa have recently been conducted [
5?
9
]. The estimated pooled prevalence of hypertension is about 30.8% in Africa [
5
] and
30.0%31.1% in Sub-Saharan Africa [
6, 10
]. Hypertension is now a significant problem in groups
previously thought to be at low risk such as rural populations, poor households and young people
[
11?13
]. It is a common cause of medical admissions in African hospitals [14]. With the ageing
population and the rising urbanization and the attendant stress, westernized diet and low
physical activity, high blood pressure will likely continue to rise [
5, 15
].
Hypertension increases steadily with increasing age. Its prevalence in the older adults in
Africa is about two to four times that in younger adults [
5, 10, 16
]. Based on the Framingham
study, it is estimated that about 90% of surviving normotensive persons aged 55 years will
develop hypertension in their lifetime [
17
]. There is insufficient information on the
cardiovascular health of older adults; a situation that partly contributes to the low attention paid to this
group [
18
]. Only one systematic review of studies in older people with hypertension in Africa
has been reported to date [
19
]. However, it did not review studies exclusively undertaken in
older adults. Instead, it reviewed studies which sampled other age groups besides those aged 55
years and older. It analyzed 39 studies using the WHO STEPwise approach to surveillance [
20
]
and 52 non-STEPS studies providing a total of 156 separate data contributions. The pooled
prevalence was 55.2% [95% confidence interval (CI) 53.1?57.4] with little variation between
younger and older age groups or over time. It is against this background that we undertook a
systematic review and meta-analysis with the aim of estimating the prevalence of hypertension
in adults aged 50 years or older in Africa and its distribution by demographic factors and over
time. Our findings could inform the development of targeted policies aimed at improving
cardiovascular health outcomes among this group.
The terms ?elderly?, ?aged? and ?older persons?, are sometimes used interchangeably in the
literature [
21
]. In most developed countries, presumably because of their higher
life-expectancy, the cut-off age 65 years is used to define older adults. The United Nations
conventionally uses 60 years as the threshold for older adults [
22
]. However, the 60 and 65
yearthresholds have been criticized as arbitrary and irrelevant for the African setting, where a
World Health Organization (WHO)-project considers 50 years to be more appropriate for
social and functional reasons [
23
]. Subsequently, several surveys in Africa have used 50 years
and older to define older adults [
16, 24, 25
].
Methods
The protocol for the systematic review, registered in PROSPERO under CRD42017056474 has
been published elsewhere [
26
].
2 / 25
Exclusion and inclusion criteria
Cross-sectional or follow-up studies published between 1 January 1980 and 28 May 2018
which reported a prevalence or incidence of hypertension in adults aged 50 years or above
living in Africa were included. Original articles, conference proceedings or abstracts reporting
the outcome of interest were also eligible for inclusion.
Hypertension was defined using the blood pressure 140/90 mmHg cut off or those taking
anti-hypertensive treatment regardless of their blood pressure on measurement [
27
]. Where
t (...truncated)